INTRODUCTION: Correct target definition is crucial in stereotactic radiotherapy for lung tumors. We evaluated use of deformable registration (DR) for target contouring on 4-dimensional (4D) CT scans. MATERIALS AND METHODS: Three clinicians contoured gross tumor volume (GTV) in an end-inspiration phase of 4DCT of 6 patients on two occasions. Two clinicians contoured GTVs in all phases of 4DCT and on maximum intensity projections (MIP). The initial GTV was auto-propagated to 9 other phases using a B-spline algorithm (VelocityAI). Internal target volumes (ITVs) generated were (i) ITV(10manual) encompassing all physician-contoured GTVs, (ii) ITV-MIP(optimized) from MIP after review of individual 4DCT phases, (iii) ITV(10deformed) encompassing auto-propagated GTVs using DR, and (iv) ITV(10deformed-optimized), from an ITV(10deformed) target that was modified to form a 'clinically optimal' ITV. Volume-overlaps were scored using Dice's Similarity Coefficients (DSCs). RESULTS: Intra-clinician GTV reproducibility was greater than inter-clinician reproducibility (mean DSC 0.93 vs. 0.88, p<0.0004). In five of 6 patients, ITV-MIP(optimized) differed from the ITV(10deformed-optimized). In all patients, the DSC between ITV(10deformed-optimized) and ITV(10deformed) was higher than that between ITV(10deformed-optimized) and ITV-MIP(optimized) (p<0.02 T-test). CONCLUSION: ITVs created in stage I tumors using DR were closer to 'clinically optimal' ITVs than was the case with a MIP-modified approach. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.
INTRODUCTION: Correct target definition is crucial in stereotactic radiotherapy for lung tumors. We evaluated use of deformable registration (DR) for target contouring on 4-dimensional (4D) CT scans. MATERIALS AND METHODS: Three clinicians contoured gross tumor volume (GTV) in an end-inspiration phase of 4DCT of 6 patients on two occasions. Two clinicians contoured GTVs in all phases of 4DCT and on maximum intensity projections (MIP). The initial GTV was auto-propagated to 9 other phases using a B-spline algorithm (VelocityAI). Internal target volumes (ITVs) generated were (i) ITV(10manual) encompassing all physician-contoured GTVs, (ii) ITV-MIP(optimized) from MIP after review of individual 4DCT phases, (iii) ITV(10deformed) encompassing auto-propagated GTVs using DR, and (iv) ITV(10deformed-optimized), from an ITV(10deformed) target that was modified to form a 'clinically optimal' ITV. Volume-overlaps were scored using Dice's Similarity Coefficients (DSCs). RESULTS: Intra-clinician GTV reproducibility was greater than inter-clinician reproducibility (mean DSC 0.93 vs. 0.88, p<0.0004). In five of 6 patients, ITV-MIP(optimized) differed from the ITV(10deformed-optimized). In all patients, the DSC between ITV(10deformed-optimized) and ITV(10deformed) was higher than that between ITV(10deformed-optimized) and ITV-MIP(optimized) (p<0.02 T-test). CONCLUSION: ITVs created in stage I tumors using DR were closer to 'clinically optimal' ITVs than was the case with a MIP-modified approach. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.
Authors: E Sala; E Mema; Y Himoto; H Veeraraghavan; J D Brenton; A Snyder; B Weigelt; H A Vargas Journal: Clin Radiol Date: 2016-10-11 Impact factor: 2.350
Authors: Frederick M Lartey; Marjan Rafat; Mohammadreza Negahdar; Andrey V Malkovskiy; Xinzhe Dong; Xiaoli Sun; Mei Li; Timothy Doyle; Jayakumar Rajadas; Edward E Graves; Billy W Loo; Peter G Maxim Journal: Radiother Oncol Date: 2016-12-15 Impact factor: 6.280
Authors: C G Vos; M Dahele; J R van Sörnsen de Koste; S Senan; I Bahce; M A Paul; E Thunnissen; E F Smit; K J Hartemink Journal: Strahlenther Onkol Date: 2013-12-22 Impact factor: 3.621
Authors: Salim Balik; Elisabeth Weiss; Nuzhat Jan; Nicholas Roman; William C Sleeman; Mirek Fatyga; Gary E Christensen; Cheng Zhang; Martin J Murphy; Jun Lu; Paul Keall; Jeffrey F Williamson; Geoffrey D Hugo Journal: Int J Radiat Oncol Biol Phys Date: 2013-02-22 Impact factor: 7.038